Carbon-13 magic angle spinning NMR evidence for a 15,15'-cis configuration of the spheroidene in the Rhodobacter sphaeroides photosynthetic reaction center

Groot, Huub J. M. de; Gebhard, R.; I, van der Hoef; Aj, Hoff; Lugtenburg, J.; Ca, Violette; Ha, Frank

doi:10.1021/bi00164a021

Cited by 47 publications

(39 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Specific isotopic labeling has been used in the study of photosynthetic reaction centers from R. sphaeroides (4,5), as well as in other systems of biophysical interest (6). The finding we report is remarkable in the sense that exceptionally large NMR signals from the active site of a large protein are obtained even in the absence of any kind of isotopic enrichment.…”

mentioning

confidence: 69%

Natural abundance solid-state carbon NMR studies of photosynthetic reaction centers with photoinduced polarization.

Zysmilich

McDermott

1996

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Solid-state NMR spectra of natural abundance 13C in reaction centers from photosynthetic bacteria Rhodobacter sphaeroides R-26 was measured. When the quinone acceptors were removed and continuous visible illumination of the sample was provided, exceptionally strong nuclear spin polarization was observed in NMR lines with chemical shifts resembling those of the aromatic carbons in bacteriochlorophyll and bacteriopheophytin. The observation of spin polarized 15N nuclei in bacteriochlorophyll and bacteriopheophytin was previously demonstrated with nonspecifically 15N-labeled reaction centers. Both the carbon and the nitrogen NMR studies indicate that the polarization is developed on species that carry unpaired electrons in the early electron transfer steps, including the bacteriochlorophyll dimer donor P860 and probably the bacteriopheophytin acceptor I. Both enhanced-absorptive and emissive polarization were seen in the carbon spectrum; most lines were absorptive but the methine carbons of the porphyrin ring (a, .3, y, 8) exhibited emissive polarization. The change in the sign of the hyperfine coupling at these sites indicates the existence of nodes in the spin density distribution on the tetrapyrrole cofactors flanking each methine carbon bridge.We previously reported that light-induced nuclear spin polarization in the 15N solid-state NMR (SSNMR) spectra of photosynthetic reaction centers made it possible to detect nitrogen nuclei located in the active site of the protein with enormous intensities not attainable under typical experimental conditions (1). These studies were done using nonspecifically labeled reaction centers in which the quinone acceptors were either missing or chemically reduced; the known photochemical cycles of the remaining bacteriochlorophyll and bacteriopheophytin donor and acceptor species make them probable candidates for radical-pair-type chemically induced dynamic nuclear polarization (CIDNP) processes (2). A paper with the chemical assignments for the 15N polarized signals is forthcoming (3). We now report the observation of photo-CIDNP that allows us to detect the SSNMR spectra of natural abundance 13C in quinone-depleted photosynthetic reaction centers from Rhodobacter sphaeroides R-26 (see Fig. 1).The study of large biological systems by SSNMR usually requires specific isotopic labeling with an NMR observable nucleus, which can be burdensome and expensive in some cases and impossible in others. Specific isotopic labeling has been used in the study of photosynthetic reaction centers from R. sphaeroides (4, 5), as well as in other systems of biophysical interest (6). The finding we report is remarkable in the sense that exceptionally large NMR signals from the active site of a large protein are obtained even in the absence of any kind of isotopic enrichment.The reaction center from R. sphaeroides R-26 is a transmembrane protein with a known structure (7), consisting of three subunits (L, M, and H) and nine cofactors (four bacteriochlorophylls, two bacteriopheophytins, two qu...

show abstract

mentioning

confidence: 69%

Natural abundance solid-state carbon NMR studies of photosynthetic reaction centers with photoinduced polarization.

Zysmilich

McDermott

1996

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…In previous work [7,44] it was argued that the 15,15'-cis configuration is the main candidate to be present in the photosynthetic reaction center of Rhodobacter sphaeroides mutant R26. In Figure 3, second panel from bottom, the calculated resonance Raman spectrum of the 15,15'-cis configuration of the truncated model is shown.…”

Section: The 1515'-cis Configurationmentioning

confidence: 99%

The Resonance Raman Spectra of Spheroidene Revisited with a First‐Principles Approach

2011

View full text Add to dashboard Cite

The resonance Raman (RR) spectra of different configurations of spheroidene are calculated by means of quantum chemical methods to investigate the nature of the cis configuration of this carotenoid molecule in the photosynthetic reaction center (RC) of the purple bacterium Rhodobacter sphaeroides. For validation of our methodology, we also calculate the spectrum of the all-trans structure present in the light-harvesting complexes of this bacterium. While former theoretical resonance Raman studies only considered truncated models of spheroidene, we report on calculations employing the full pigment here. The calculated frequencies for the all-trans configuration are in good agreement with former experimental and simulated data. Among the possible cis structures, the 15,15'-cis configuration shows a RR spectrum that is in best agreement with the experimental spectrum of spheroidene in the RC. In order to assess model truncation effects, we compare calculations for the full spheroidene molecule to those for the truncated model. While the main features can already be found in the latter, the full model leads to considerably different intensities in the region around 1150 cm(-1), which improve the agreement with experiment. A slight mismatch for the vibrational frequencies in the C=C stretch region is investigated by considering a model for spheroidene in the binding pocket comprising more than 500 atoms in total. The results do not lead to improved agreement with experiment, in contrast to the simpler strategy of introducing constraints in the structural optimization of a truncated spheroidene model. The calculated RR spectrum of the 13,14-cis configuration shows additional features which can also be identified in the experimental RR spectrum. This shows that the most likely cis structure is the 15,15'-cis configuration. Besides this, the 13,14-cis configuration remains a candidate for an additional spheroidene structure in the RC of Rhodobacter sphaeroides mutant R26.

show abstract

“…[10Ϫ12] This determination first of all requires the sufficient availability of specifically labeled [5][6][7][8][9][10][11][12][13] C]-and [6-13 C]ubiquinone-10.…”

Section: Introductionmentioning

confidence: 99%

“…Since it was not possible to prepare these specifically [5][6][7][8][9][10][11][12][13] C]-and [6-13 C]-labeled ubiquinones-10 efficiently by the synthetic schemes reported earlier, [2,13] novel schemes had to be developed. These novel schemes for the preparation of [5][6][7][8][9][10][11][12][13] C]-and [6-13 C]ubiquinone-10 are discussed in this paper.…”

Section: Introductionmentioning

confidence: 99%

“…These novel schemes for the preparation of [5][6][7][8][9][10][11][12][13] C]-and [6-13 C]ubiquinone-10 are discussed in this paper. The new synthetic scheme for [5][6][7][8][9][10][11][12][13] C]ubiquinone-10 was extendable to enable the preparation of ubiquinones-10 13 C-labeled at any single position and in all combinations of positions in the quinone ring. This should be invaluable for a full vibration analysis of the quinone ring system in the near future.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis and Spectroscopic Characterization of [5-13C]- and [6-13C]Ubiquinone-10 for Studies of Bacterial Photosynthetic Reaction Centers

et al. 2002

Self Cite

View full text Add to dashboard Cite

This paper presents the synthesis and characterization by mass spectrometry and NMR spectroscopy of [2-13 C]-and [3-13 C]ubiquinone-0 and of [5-13 C]-and [6-13 C]ubiquinone-10. A scheme based on the synthetic approach to [5-13 C]ubiquinone-10 has been worked out for the synthesis of ubiquinones 13 C-labeled at any individual position and at every combination of positions in the quinone ring. The [5-13 C]-and [6-13 C]ubiquinone-10 isotopomers were incorporated

show abstract

Carbon-13 magic angle spinning NMR evidence for a 15,15'-cis configuration of the spheroidene in the Rhodobacter sphaeroides photosynthetic reaction center

Cited by 47 publications

References 31 publications

Natural abundance solid-state carbon NMR studies of photosynthetic reaction centers with photoinduced polarization.

Natural abundance solid-state carbon NMR studies of photosynthetic reaction centers with photoinduced polarization.

The Resonance Raman Spectra of Spheroidene Revisited with a First‐Principles Approach

Synthesis and Spectroscopic Characterization of [5-13C]- and [6-13C]Ubiquinone-10 for Studies of Bacterial Photosynthetic Reaction Centers

Contact Info

Product

Resources

About